Hi
I'm new to dismantling K100 engines but am having a very good attempt at getting an abused (not by me) K100RT restored and back on the road. I've taken most of it apart and now have some questions. Many more will probably follow!

Firstly, throttle bodies. I've taken pictures (but can't work out how to attach them here - any ideas?) 

Looking at the bodies from the top there is some black discolouration inside in the first 2 chambers. From the underside, the first two are really gunked up with dirt and black oily stuff. Is this normal?
Should I worry?
Do I need to take strip the engine further or should I just clean them up, check valve clearances and rebuild?

I sure that the rubber parts on the bodies are knackered so will replace when I replace other worn items on rebuild.

Any advice greatly appreciated.
Cheers...
Foilopog

Hey,

others who know stuff will tell you about the TBs

I can search the forum so here is my contribution.

https://www.k100-forum.com/t998-posting-pictures-and-movies#5126

Many thanks for replies. Here's a picture of the throttle bodies I mentioned...

1456615_10151751003692181_1037104210_n.jpg

1460035_10151751003702181_1400716200_n.jpg

Would love to know if normal - all the rubbers etc were original and in a very poor state.

Cheers...

Foilopog

Make sure the valve clearances are correct that looks to me as if the riding valves have been sending some combustion back to the throttle bodies.

looks as though there has been a bit of blowback happening ..possibly from an over tight inlet valve
or the valve is actually  not seating correctly now with a bit of wear between seat and valve ?.

I would pull the cam cover on the head and do a little measuring before anything else

I have seen similar on 3 sets of throttle bodies I have pulled apart recently also (but more usually at the other end of the  set ...where oil vapour is returned through the intake tract from the oil breather introduction to the plenum )
I guess oil vapour sticks to the bore a bit more down that end and deposits more gunk durring the cycle

the cams have a good bit of overlap and a good bit of early opening + the ignition fires on the alternate stroke in any case ....which could also mean that the fuel in the inlet path (from the 4 times a cycle injection ) could be partially igniting with the valve not sealing properly ?

or is it just not evacuating all on the exhaust stroke ( ie restriction down the exhaust pipe or weak - misfiring ignition ...)

just some hypothetical guess to explain the phenomena